Boiler furnace



June 26, 1934. E, BAlLEY BOILER FURNACE Original Filed Jan. 27, 1927 2Sheets-Sheet 1 gm INVENTOR.

Y ANORA/1516.9.

E. G. BAILEY BOILER FURNACE June 26, 1934.

2 Sheets-Sheet 2 Original Filed Jan. 27, 1927 ygiyf Z.

W 1r 1 ATTORNEYSS Patented June 26, 1934 BOILER FURNACE Ervin G. Bailey,Easton, Pa., assignor to Fuller Lehigh Company, New York, N. Y., acorporation of Delaware Application January 27,

1927, Serial No. 163,867

Renewed November 14, 1931 4 Claims.

" This invention relates to a boiler furnace, one or more walls of whichare kept cool by water tubes connected to the circulation system of theboiler, and through which there is also a local 5 circulation of water.The invention will be understood from the description in connection withthe accompanying drawings, in which Fig. 1 is a side view partly insection showing an illustrative embodiment of the invention, and Fig. 2'

is a front view of the same.

The invention will be described in connection with a Stirling boiler,but it is to be understood that it is applicable to boilers of othertypes. In the drawings, reference characters 5, 6 and '7 indicate thethree upper drums of a Stirling boiler, of which the lower or mud drumis shown at 8. These drums are connected by banks of tubes 9, 10 and'lland tubes 12 and 13 connect the upper drums. The boiler is provided withthe usual baffles and outlet for waste products of combustion and alsowith a superheater.

A furnace 15 is located below the boiler and is illustrated as beingprovided with a chain grate stoker 16, although it is to be understoodthat the furnace may be provided with oil, gas or fuel burners ifdesired. A row of tubes 17 extends along the front wall of the furnace,and is lined on the inside with refractory material 18 that i may bemade, for example, in the form of blocks 30 having a metal back tocontact with the tubes and faces of refractory material toward theinside of the furnace. The upper ends of the tubes 17 are connected to aheader 191 and .the lower ends to a header 20. A tube 21 outside of theboiler setting connects the drum 8 to the header and a tube 22,preferably less in cross sectional area than the row of furnace walltubes, outside of the boiler connects the headers 19 and 20,

while the tube 23 connects the header 19 to theupper drum 7. A valveddrain provided for the header 20.

The operation is as follows: Feed water is introduced into the boiler atany convenient point, and hot products of combustion from the'furnacepassing across the banks of tubes 9, l0 and 11 generate steam. Waterpasses from the drum 8 through the tube 21 into the header 20, andthence into the tubes 17 where it receives heat from the furnace 15 andthe mixture of steam and water rises into the header 19, where they arepartially separated, the steam for the most part passing through thetube 23 into the drum 7 and most of the water passing downwardly throughthe tube 22 into the header 20. There 55 is thus a local circulation ofwater through the pipe 24 may be tubes 17- and 22 in addition to thewater that" passes from the tube 21 into the header 20 and tubes 17.

I have found that in order to obtain satisfactory local circulation inthe tubes 17 and 22 it is necessary to have the friction in the tube 23of considerable magnitude. This may be accomplished by having this tube23 of small size or by having a valve or restricted orifice therein thatwill provide the By preventing too much water from flowing up wardsthrough tube 23, the static head in thl tubes 17, that arises because ofthe difference in the density of the water in tube-21, etc., and thetubes 17, always exceeds the friction in these 7 tubes 17, so that waterwill constantly circulate upwardly through tubes 17 and downwardlythrough tube 22 while the furnace is operating. For example,satisfactory results have been obtained by so restricting the flowthrough tube 23 that about 9 parts of steam to 1 part of water by volume(or 9 parts water to 1 part steam by weight), at pressure of 225 pounds,would flow upwardly through tube 23. Under these conditions the flow ofwater downward through tube 22 is practically all water and representsabout 80 times as much by weight as the steam gener ated. The flowupward through tubes 17 is a mixture of steam and water with about 93times as much water by weight as there is steam generated. On a volumebasis this is equivalent to approximately 48% water and 52% steam at theupper end of tube 17. A steam volume of not over 50% at this point hasbeen found to be a safe figure and the pipes are made of such sizes asto produce this condition. Also,-restricting the tube 23 so thatapproximately equal volumes of water and steam pass through it, has beenfound to be a condition that will cause satisfactory local circulationto take place.

The following are some of the advantages that have been obtained byusing this invention:

(a) Due to the fact that the boiler water circulates through the furnacewall tubes, the concentration of impurities in all portions of the waterremains approximately the same as that in other portions:

(1)) The small amount of water that is returned through the restrictedtube 23 does not agitate the water in the drum 7 so much as to producean appreciable increase in the wetness of the steam that is withdrawnfrom the boiler:

(c) Sufilcient recirculation will take place in the tubes 17 when theboiler is starting up and before it begins to steam, so that the dangerof the tubes 17 being burned out is eliminated:

(d) The small size and low cost of tubes 21 and 23 permit greatflexibility for expansion between boiler ond walls by reason of theirsmall size, and more satisfactory connection to the boiler drums can besecured since the, tubes are small enough to be expanded directly intothe drums without the use of saddles or nozzles required by largerpipes.

I claim: I

1. In combination, a vapor generator comprising a plurality of upperdrums and at least one lower drum with tube banks connecting the upperand lower drums and having a maintained liquid level, furnace wallsenclosing a combustion chamber arranged to burn solid fuel in a bed forheating said generator, furnace wall protecting tubes having the majorlengths above said fuel bed and spaced along the combustion chamber sideof at least one of the walls, compartments, one connecting the upperadjacent ends of said tubes and the other the lower adjacent ends, bothsubmerged beneath the liquid level of the boiler drums, a connectionfrom the upper compartment to the generator proportioned to take awayonly part of the liquid caused to move upwardly of the tubes by heat ofcombustion, a connection between the compartments returning theremainder of the liquid to the lower compartment, and a supplyconnection from the lower drum of the boiler to the protecting tubesconstantly replacing with liquid any liquid and vaport removed from theupper compartment.

2. In combination, a vapor generator comprising a plurality of upperdrums and at least one lower drum with tube banks connecting the upperand lower drums and having a maintained liquid level, furnace wallsenclosing a combustion chamber arranged to burn solid fuel in a bed forheating said generator, furnace wall protecting tubes spaced along thecombustion chamber side of at least one of the walls and in thecombustion chamber area, compartments, one connecting the upper adjacentends of said tubes and the other the lower adjacent ends, both submergedbeneath the liquid level of the boiler drums, a connection from theupper compartment to the generator proportioned to take away only partof the liquid caused to move upwardly of the tubes by heat ofcombustion, a connection between the compartments returning theremainder of the liquid to the lower compartment, and a supplyconnectionfrom the lower drum of the boiler to the protecting tubesconstantly replacing with liquid any liquid and vapor removed from theupper compartment. 80

3. In combination, a vapor generator including a vapor and liquidseparator having a maintained liquid level and a lower liquid chamberwith a bank of tubes connecting the separator and chamber, furnace wallsenclosing a com- 5 bustion chamber arranged to burn solid fuel in a bedfor heating said generator, furnace wall protecting tubes spaced alongthe combustion chamber side of at least one of said walls and having themajor portion of their lengths above the solid fuel bed, compartments,one connecting the upper adjacent ends of said tubes and the other thelower adjacent ends, both submerged beneath the liquid level of theboiler, a connection from the upper compartment to the generator proportioned to take away only part of the liquid caused to move upwardly ofthe tubes by heat of combustion, a connection between the compartmentsreturning the remainder of the liquid to the lower compartment, and asupply connection from the lower chamber of the boiler to the protectingtubes constantly replacing with liquid any liquid and vapor moved fromthe upper compartment.

4. In combination, a vapor generator including a vapor and liquidseparator having a maintained liquid level and a lower liquid chamberwith a bank of tubes connecting the separator and chamber, furnace wallsenclosing a combustion chamber arranged to burn solid fuel in a movingbed in said furnace for heating said generator, furnace wall protectingtubes spaced along the combustion chamber side of at leastthe wallopposite the advancing solid fuel bed, compartments, one connecting theupper adjacent ends of said tubes and the other the lower adjacent ends,both submerged beneath the liquid level of the boiler, a connection fromthe upper compartment to the generator proportioned to take away onlypart of the liquid caused to move upwardly of the tubes by heat ofcombustion, a connection between the compartments returning theremainder of the liquid to the lower compartment, and a supplyconnection from the lower chamber of the boiler to the protecting tubesconstantly replacing with liquid any liquid and vapor removed from theupper compartment.

ERVIN G. BAILEY.

